XENO S3A Flickering after 2 years - Need repair advice

Hello - I need some advice on my XENO S3A 18650 flashlight.

I've had it for 2 years and its been great up till now. Its got fantastic color temperature (around 3000K), the battery lasts forever, and its super bright.

About 3 months ago it started flickering. Its gotten progressively worse and its basically unusable now. I think the problem may be in the switch. This is what I've tried:
- unscrew the endcap/switch and clean off the inside of the housing and switch contact area.
- unscrew the bezel and clean/inspect solder joints on the LED
- pulled on the springs to make sure theyre still springy and are getting good contact

I've noticed that i can get it to work a little if I screw the endcap on extra tight, but it still doesn't work well.

Any suggestions on what I should do next?

I really don't want to give up on it because its the smallest 18650 light I can find with a warm color temp LED. I use it for macro photography of insects and the warm light makes for better photos. The small size is nice because I can hold it between my ring and pinky fingers and hold a camera at the same time.

Thanks!
-Jordan

Also - I contacted XENO and got no response.

Do the 'paperclip test' to check it's definitely the tailcap - with the tailcap removed, connect the -ve end of the cell to the bare aluminium on the end of the body tube; if it no longer flickers, the tailcap/switch is the culprit.

My Xeno G42 came with a replacement switch, does the S3A? You might be able to find a cheap replacement switch online if not.

Edit: just spotted the S3A tailcap is male threaded. Weird. The paperclip test will still work, but might be a bit of a PITA.